Test Equipment Anonymous (TEA) group therapy thread

[med6753]

I had to get into the TEA closet and tidy it up. It was starting to look like a garbage dump. But after the clean up it's obvious that I'm running out of room everywhere. 

[VK5RC]

Bring out the........ nice warm cup of tea!  Arrrrggggghhhh.

[Cerebus]

On a completely different note.

I was cleaning off some breadboards yesterday to clear the way for doing some actual prototyping work and in the process of stripping them down found an AD586 5V voltage reference on one of them. I bought a couple some time back and, at the time, didn't have a voltmeter with either enough precision or accuracy to judge how close to 'the truth' they were as they came out of the factory. That is no longer true, I've now got the Agilent 34461A so for fun I thought I'd run them against it.

Now, we've all heard that people like AD and LT (now one and the same) tend to produce stuff that's a lot better than nominal specifications would suggest, as long as you're talking about one of the better spec variants rather than the stuff that's been deliberately binned as lower grade. OK, so this is going to be anecdote rather than evidence but I thought it would be informative to see if that was true for these parts.

These two are AD586LNs, so the 2nd best grade out of 4 grades (the best grade is ±2mV and 2 ppm/ºC) - the nominal spec for this grade is ±2.5 mV and 5 ppm/ºC. So I measured both references - sample 1 was 5.000 018 V (3.6 ppm high), sample 2 was 4.999843 V (31.3 ppm low). Pretty good for parts with a nominal 500 ppm (0.05%) tolerance.

For completeness  - the uncertainties on the 34461A for this reading, range and time since cal (2 yr) are ±260 uV for k=2.

[tggzzz]

And I kindly invite them to go piss up a rope. 

Ah, is this some pastime from your youth? Like seeing who can piss the highest? 

By the way, I think I've figured out why specmaster is getting so hot under the collar about anything with more than 3 ¹/₂ digits. I fear that the poor lad has reached that age where, by the time he gets to read the 4^th digit, he's forgotten the 1^st. 

Good job I'd just put my coffee down.

I'd be a little kinder and mention things like "is 9.999571 43ppm or 430ppm low?", or "is 0.002% 2ppm, 20ppm or 200ppm?". No, there is absolutely no reason whatsoever why I think of those examples.

[Cerebus]

There's an interesting bit of cognition going on there. If something is 'a bit over' some round figure (i.e. usual 1, 2, or 5 x 10ⁿ progression) I can usually work out the %age over, or even ppm over, in my head. If it's 'a bit under' I usually have to reach for a calculator unless it's only in the last one or two decimal places that it's off. With a positive offset I can handle almost any number of digits in my head and get a correct result 99.9% of the time. In the negative offset (e.g. 4.998 versus nominal 5.000), even for single digits, I find it easy to make silly mistakes that I'd never make for the positive equivalent (e.g. 5.002).

[bd139]

Ok all done here. Firstly, after the comments about bacon earlier, bacon was consumed. This fuelled the soldering fury inside the HM307 which is now less likely to explode in my face or piss electrolyte everywhere. Most of the larger and more furious looking electrolytics are replaced.



Still needs more cleaning but it’ll do for now.

Edit: oh also the burned resistor there had the nasty cap on the end of it. Running warm now not hot 

And back to work...

[tggzzz]

To me a good description of TAoE that, only greybeards will understand, is to remember the old Markus compendiums of circuits. They contained thousands of "naked" schematics, which sounds exactly what a practicing engineer might want so they didn't have to (poorly) reinvent a wheel, and to solve their problem using a circuit that would probably work well.

But in practice the Markus' compendiums were a great disappointment and of little use, because there was no description of how the circuits worked, nor their performance, nor their limitations.

TAoE avoids that trap by having the explanations. Hence TAoE useful when you want to find a circuit that Just Works.

OTOH, TAoE by design is not a good book for understanding fundamental electronics and theory, nor for understanding the depths of any particular subject.

Spot on. The accompanying lab book is designed for the latter. There's a lot to learn in there as well. I own a copy of that too.

No lab book nor the x-chapters could satisfy what I'm thinking of there. Examples would be things like Sklar's DIGITAL COMMUNICATIONS Fundamentals and Applications with contents: 

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1  SIGNALS AND SPECTRA
1.1 Digital Communication Signal Processing, 3
1.1.1 Why Digital?, 3
1.1.2 Typical Block Diagram and Transformations, 4
1.1.3 Basic Digital Communication Nomenclature, 11
1.1.4 Digital versus Analog Performance Criteria, 13
1.2 Classification of Signals, 14
1.2.1 Deterministic and Random Signals, 14
1.2.2 Periodic and Nonperiodic Signals, 14
1.2.3 Analog and Discrete Signals, 14
1.2.4 Energy and Power Signals, 14
1.2.5 The Unit Impulse Function, 16
1.3 Spectral Density, 16
1.3.1 Energy Spectral Density, 17
1.3.2 Power Spectral Density, 17
1.4 Autocorrelation, 19
1.4.1 Autocorrelation of an Energy Signal, 19
1.4.2 Autocorrelation of a Periodic (Power) Signal, 20
1.5 Random Signals, 20
1.5.1 Random Variables, 20
1.5.2 Random Processes, 22
1.5.3 Time Averaging and Ergodicity, 25
1.5.4 Power Spectral Density of a Random Process, 26
1.5.5 Noise in Communication Systems, 30
1.6 Signal Transmission through Linear Systems, 33
1.6.1 Impulse Response, 34
1.6.2 Frequency Transfer Function, 35
1.6.3 Distortionless Transmission, 36
1.6.4 Signals, Circuits, and Spectra, 42
1.7 Bandwidth of Digital Data, 45
1.7.1 Baseband versus Bandpass, 45
1.7.2 The Bandwidth Dilemma, 47
1.8 Conclusion, 51
2 FORMATTING AND BASEBAND MODULATION
2.1 Baseband Systems, 56
2.2 Formatting Textual Data (Character Coding), 58
2.3 Messages, Characters, and Symbols, 61
2.3.7 Example of Messages, Characters, and Symbols,
2.4 Formatting Analog Information, 62
2.4.1 The Sampling Theorem, 63
2.4.2 Aliasing, 69
2.4.3 Why Oversample? 72
2.4.4 Signal Interface for a Digital System, 75
2.5 Sources of Corruption, 76
2.5.7 Sampling and Quantizing Effects, 76
2.5.2 Channel Effects, 77
2.5.3 Signal-to-Noise Ratio for Quantized Pulses, 78
2.6 Pulse Code Modulation, 79
2.7 Uniform and Nonuniform Quantization, 81
2.7.7 Statistics of Speech Amplitudes, 81
2.7.2 Nonuniform Quantization, 83
2.7.3 Companding Characteristics, 84
2.8 Baseband Modulation, 85
2.8.1 Waveform Representation of Binary Digits, 85
2.8.2 PCM Waveform Types, 85
2.8.3 Spectral Attributes of PCM Waveforms, 89
2.8.4 Bits per PCM Word and Bits per Symbol, 90
2.8.5 M-ary Pulse Modulation Waveforms, 91
2.9 Correlative Coding, 94
2.9.7 Duobinary Signaling, 94
2.9.2 Duobinary Decoding, 95
2.9.3 Preceding, 96
2.9.4 Duobinary Equivalent Transfer Function, 97
2.9.5 Comparison of Binary with Duobinary Signaling,2.9.6 Poly binary Signaling, 99
2.10 Conclusion, 100
3  BASEBAND DEMODULATION/DETECTION
3.1 Signals and Noise, 106
3.1.1 Error-Performance Degradation in Communication Systems, 106
3.1.2 Demodulation and Detection, 107
3.1.3 A Vectorial View of Signals and Noise, 110
3.1.4 The Basic SNR Parameter for Digital Communication Systems, 117
3.1.5 Why Eb/N0 Is a Natural Figure of Merit, 118
3.2 Detection of Binary Signals in Gaussian Noise, 119
3.2.1 Maximum Likelihood Receiver Structure, 119
3.2.2 The Matched Filter, 122
3.2.3 Correlation Realization of the Matched Filter, 124
3.2.4 Optimizing Error Performance, 127
3.2.5 Error Probability Performance of Binary Signaling, 131
3.3 Intersymbol Interference, 136
3.3.1 Pulse Shaping to Reduce ISI, 138
3.3.2 Two Types of Error-Performance Degradation, 142
3.3.3 Demodulation/Detection of Shaped Pulses, 145
3.4 Equalization, 149
3.4.1 Channel Characterization, 149
3.4.2 Eye Pattern, 151
3.4.3 Equalizer Filter Types, 152
3.4.4 Preset and Adaptive Equalization, 158
3.4.5 Filter Update Rate, 160
3.5 Conclusion, 161
4BANDPASS MODULATION AND DEMODULATION/DETECTION
4.1 Why Modulate? 168
4.2 Digital Bandpass Modulation Techniques, 169
4.2.1 Phasor Representation of a Sinusoid, 171
4.2.2 Phase Shift Keying, 173
4.2.3 Frequency Shift Keying, 175
4.2.4 Amplitude Shift Keying, 175
4.2.5 Amplitude Phase Keying, 176
4.2.6 Waveform Amplitude Coefficient, 176
4.3 Detection of Signals in Gaussian Noise, 177
4.3.1 Decision Regions, 177
4.3.2 Correlation Receiver, 178
4.4 Coherent Detection, 183
4.4.1 Coherent Detection of PSK, 183
4.4.2 Sampled Matched Filter, 184
4.4.3 Coherent Detection of Multiple Phase Shift Keying, 188
4.4.4 Coherent Detection of FSK, 191
4.5 Noncoherent Detection, 194
4.5.1 Detection of Differential PSK, 194
4.5.2 Binary Differential PSK Example, 196
4.5.3 Noncoherent Detection of FSK, 198
4.5.4 Required Tone Spacing for Noncoherent Orthogonal FSK,
4.6 Complex Envelope, 204
4.6.1 Quadrature Implementation of a Modulator, 205
4.6.2 D8PSK Modulator Example, 206
4.6.3 D8PSK Demodulator Example, 208
4.7 Error Performance for Binary Systems, 209
4.7.1 Probability of Bit Error for Coherently Detected BPSK,
4.7.2 Probability of Bit Error for Coherently Detected Differentially Encoded Binary PSK, 211
4.7.3 Probability of Bit Error for Coherently Detected Binary Orthogonal FSK, 213
4.7.4 Probability of Bit Error for Noncoherently Detected Binary Orthogonal FSK, 213
4.7.5 Probability of Bit Error for Binary DPSK, 216
4.7.6 Comparison of Bit Error Performance for Various Modulation Types, 218
4.8 M-ary Signaling and Performance, 219
4.8.1 Ideal Probability of Bit Error Performance, 219
4.8.2 M-ary Signaling, 220
4.8.3 Vectorial View of MPSK Signaling, 222
4.8.4 BPSK and QPSK Have the Same Bit Error Probability,4.8.5 Vectorial View of MFSK Signaling, 225
4.9 Symbol Error Performance for M-ary Systems (M > 2), 229
4.9.1 Probability of Symbol Error for MPSK, 229
4.9.2 Probability of Symbol Error for MFSK, 230
4.9.3 Bit Error Probability versus Symbol Error Probability for Orthogonal Signals, 232
4.9.4 Bit Error Probability versus Symbol Error Probability for Multiple Phase Signaling, 234
4.9.5 Effects of Intersymbol Interference, 235
4.10 Conclusion, 236
5 COMMUNICATIONS LINK ANALYSIS
5.1 What the System Link Budget Tells the System Engineer,
5.2 The Channel, 244
5.2.1 The Concept of Free Space, 244
5.2.2 Error-Performance Degradation, 245
5.2.3 Sources of Signal Loss and Noise, 245
5.3 Received Signal Power and Noise Power, 250
5.3.1 The Range Equation, 250
5.3.2 Received Signal Power as a Function of Frequency, 254
5.3.3 Path Loss is Frequency Dependent, 256
5.3.4 Thermal Noise Power, 258
5.4 Link Budget Analysis, 259
5.4.1 Two E//NQ Values of Interest, 262
5.4.2 Link Budgets are Typically Calculated in Decibels, 263
5.4.3 How Much Link Margin is Enough? 264
5.4.4 Link Availability, 266
5.5 Noise Figure, Noise Temperature, and System Temperature, 270
5.5J Noise Figure, 270
5.5.2 Noise Temperature, 273
5.5.3 Line Loss, 274
5.5.4 Composite Noise Figure and Composite Noise Temperature, 276
5.5.5 System Effective Temperature, 277
5.5.6 Sky Noise Temperature, 282
5.6 Sample Link Analysis, 286
5.6.1 Link Budget Details, 287
5.6.2 Receiver Figure of Merit, 289
5.6.3 Received Isotropic Power, 289
5.7 Satellite Repeaters, 290
5.7.7 Nonregenerative Repeaters, 291
5.7.2 Nonlinear Repeater Amplifiers, 295
5.8 System Trade-Offs, 296
5.9 Conclusion, 297
6 CHANNEL CODING: PART 1
6.1 Waveform Coding and Structured Sequences, 305
6.1.1 Antipodal and Orthogonal Signals, 307
6.1.2 M-ary Signaling, 308
6.1.3 Waveform Coding, 309
6.1.4 Waveform-Coding System Example, 313
6.2 Types of Error Control, 315
6.2.1 Terminal Connectivity, 315
6.2.2 Automatic Repeat Request, 316
6.3 Structured Sequences, 317
6.3.1 Channel Models, 318
6.3.2 Code Rate and Redundancy, 320
6.3.3 Parity Check Codes, 321
6.3.4 Why Use Error-Correction Coding? 323
6.4 Linear Block Codes, 328
6.4.1 Vector Spaces, 329
6.4.2 Vector Subspaces, 329
6.4.3 A (6, 3) Linear Block Code Example, 330
6.4.4 Generator Matrix, 331
6.4.5 Systematic Linear Block Codes, 333
6.4.6 Parity-Check Matrix, 334
6.4.7 Syndrome Testing, 335
6.4.8 Error Correction, 336
6.4.9 Decoder Implementation, 340
6.5 Error-Detecting and Correcting Capability, 342
6.5.1 Weight and Distance of Binary Vectors, 342
6.5.2 Minimum Distance of a Linear Code, 343
6.5.3 Error Detection and Correction, 343
6.5.4 Visualization of a 6-Tuple Space, 347
6.5.5 Erasure Correction, 348
6.6 Usefulness of the Standard Array, 349
6.6.1 Estimating Code Capability, 349
6.6.2 An (n, k) Example, 351
6.6.3 Designing the (8, 2) Code, 352
6.6.4 Error Detection versus Error Correction Trade-Offs, 352
6.6.5 The Standard Array Provides Insight, 356
6.7 Cyclic Codes, 356
6.7.7 Algebraic Structure of Cyclic Codes, 357
6.7.2 Binary Cyclic Code Properties, 358
6.7.3 Encoding in Systematic Form, 359
6.7.4 Circuit for Dividing Polynomials, 360
6.7.5 Systematic Encoding with an (n - k)-Stage Shift Register, 363
6.7.6 Error Detection with an (n - k)-Stage Shift Register, 365
6.8 Weil-Known Block Codes, 366
6.8.1 Hamming Codes, 366
6.8.2 Extended Golay Code, 369
6.8.3 BCH Codes, 370
6.9 Conclusion, 374
7 CHANNEL CODING: PART 2
7.1 Convolutional Encoding, 382
7.2 Convolutional Encoder Representation, 384
7.2.1 Connection Representation, 385
7.2.2 State Representation and the State Diagram, 389
7.2.3 The Tree Diagram, 391
7.2.4 The Trellis Diagram, 393
7.3 Formulation of the Convolutional Decoding Problem, 395
7.3.1 Maximum Likelihood Decoding, 395
7.3.2 Channel Models: Hard versus Soft Decisions, 396
7.3.3 The Viterbi Convolutional Decoding Algorithm, 401
7.3.4 An Example of Viterbi Convolutional Decoding, 401
7.3.5 Decoder Implementation, 405
7.3.6 Path Memory and Synchronization, 408
7.4 Properties of Convolutional Codes, 408
7.4.1 Distance Properties of Convolutional Codes, 408
7.4.2 Systematic and Nonsystematic Convolutional Codes, 413
7.4.3 Catastrophic Error Propagation in Convolutional Codes, 414
7.4.4 Performance Bounds for Convolutional Codes, 415
7.4.5 Coding Gain, 416
7.4.6 Best Known Convolutional Codes, 418
7.4.7 Convolutional Code Rate Trade-Off, 420
7.4.8 Soft-Decision Viterbi Decoding, 420
7.5 Other Convolutional Decoding Algorithms, 422
7.5.1 Sequential Decoding, 422
7.5.2 Comparisons and Limitations of Viterbi and Sequential Decoding,7.5.3 Feedback Decoding, 427
7.6 Conclusion, 429
8 CHANNEL CODING: PART 3
8.1 Reed-Solomon Codes, 437
8.1.1 Reed-Solomon Error Probability, 438
8.1.2 Why R-S Codes Perform Well Against Burst Noise, 441
8.1.3 R-S Performance as a Function of Size, Redundancy, and Code Rate, 441
8.1.4 Finite Fields, 445
8.1.5 Reed-Solomon Encoding, 450
8.1.6 Reed-Solomon Decoding, 454
8.2 Interleaving and Concatenated Codes, 461
8.2.1 Block Interleaving, 463
8.2.2 Convolutional Interleaving, 466
8.2.3 Concatenated Codes, 468
8.3 Coding and Interleaving Applied to the Compact Disc Digital Audio System, 469
8.3.1 CIRC Encoding, 470
8.3.2 CIRC Decoding, 472
8.3.3 Interpolation and Muting, 474
8.4 Turbo Codes, 475
8.4.1 Turbo Code Concepts, 477
8.4.2 Log-Likelihood Algebra, 481
8.4.3 Product Code Example, 482
8.4.4 Encoding with Recursive Systematic Codes, 488
8.4.5 A Feedback Decoder, 493
8.4.6 The MAP Decoding Algorithm, 498
8.4.7 MAP Decoding Example, 504
8.5 Conclusion, 509
Appendix 8A The Sum of Log-Likelihood Ratios, 510
9 MODULATION AND CODING TRADE-OFFS
9.1 Goals of the Communications System Designer, 521
9.2 Error Probability Plane, 522
9.3 Nyquist Minimum Bandwidth, 524
9.4 Shannon-Hartley Capacity Theorem, 525
9.4.1 Shannon Limit, 528
9.4.2 Entropy, 529
9.4.3 Equivocation and Effective Transmission Rate, 532
9.5 Bandwidth Efficiency Plane, 534
9.5.7 Bandwidth Efficiency ofMPSK and MFSK Modulation,
9.5.2 Analogies Between Bandwidth-Efficiency and Error Probability Planes, 536
9.6 Modulation and Coding Trade-Offs, 537
9.7 Defining, Designing, and Evaluating Digital Communication Systems, 538
9.7.7 M-ary Signaling, 539
9.7.2 Bandwidth-Limited Systems, 540
9.7.3 Power-Limited Systems, 541
9.7.4 Requirements for MPSK and MFSK Signaling, 542
9.7.5 Bandwidth-Limited Uncoded System Example, 543
9.7.6 Power-Limited Uncoded System Example, 545
9.7.7 Bandwidth-Limited and Power-Limited Coded System Example, 547
9.8 Bandwidth-Efficient Modulation, 555
9.5.7 QPSK and Offset QPSK Signaling, 555
9.8.2 Minimum Shift Keying, 559
9.8.3 Quadrature Amplitude Modulation, 563
9.9 Modulation and Coding for Bandlimited Channels, 566
9.9.7 Commercial Telephone Modems, 567
9.9.2 Signal Constellation Boundaries, 568
9.9.3 Higher Dimensional Signal Constellations, 569
9.9.4 Higher-Density Lattice Structures, 572
9.9.5 Combined Gain: N-Sphere Mapping and Dense Lattice,9.10 Trellis-Coded Modulation, 573
9.70.7 The Idea Behind Trellis-Coded Modulation (TCM),9.10.2 TCM Encoding, 576
9.10.3 TCM Decoding, 580
9.10.4 Other Trellis Codes, 583
9.10.5 Trellis-Coded Modulation Example, 585
9.10.6 Multi-Dimensional Trellis-Coded Modulation, 589
9.11 Conclusion, 590
10 SYNCHRONIZATION
10.1 Introduction, 599
10.1.1 Synchronization Defined, 599
10.1.2 Costs versus Benefits, 601
10.1.3 Approach and Assumptions, 602
10.2 Receiver Synchronization, 603
10.2.1 Frequency and Phase Synchronization, 603
10.2.2 Symbol Synchronization—Discrete Symbol Modulations, 625
10.2.3 Synchronization with Continuous-Phase Modulations (CPM), 10.2.4 Frame Synchronization, 639
10.3 Network Synchronization, 643
10.3.1 Open-Loop Transmitter Synchronization, 644
10.3.2 Closed-Loop Transmitter Synchronization, 647
10.4 Conclusion, 649
11 MULTIPLEXING AND MULTIPLE ACCESS
11.1 Allocation of the Communications Resource, 657
11.1.1 Frequency-Division Multiplexing/Multiple Access, 660
11.1.2 Time-Division Multiplexing/Multiple Access, 665
11.1.3 Communications Resource Channelization, 668
11.1.4 Performance Comparison ofFDMA and TDMA, 668
11.1.5 Code-Division Multiple Access, 672
11.1.6 Space-Division and Polarization-Division Multiple Access, 674
11.2 Multiple Access Communications System and Architecture, 676
11.2.1 Multiple Access Information Flow, 677
11.2.2 Demand Assignment Multiple Access, 678
11.3 Access Algorithms, 678
11.3.1 ALOHA, 678
11.3.2 Slotted ALOHA, 682
11.3.3 Reservation-ALOHA, 683
11.3.4 Performance Comparison ofS-ALOHA and R-ALOHA, 684
11.3.5 Polling Techniques, 686
11.4 Multiple Access Techniques Employed with INTELSAT, 689
11.4.1 Preassigned FDM/FM/FDMA or MCPC Operation, 690
11.4.2 MCPC Modes of Accessing an INTELSA T Satellite, 690
11.4.3 SPADE Operation, 693
11.4.4 TDMA in INTELSAT, 698
11.4.5 Satellite-Switched TDMA in INTELSAT, 704
9.10.5 Trellis-Coded Modulation Example, 585
9.10.6 Multi-Dimensional Trellis-Coded Modulation, 589
9.11 Conclusion, 590
10 SYNCHRONIZATION
10.1 Introduction, 599
10.1.1 Synchronization Defined, 599
10.1.2 Costs versus Benefits, 601
10.1.3 Approach and Assumptions, 602
10.2 Receiver Synchronization, 603
10.2.1 Frequency and Phase Synchronization, 603
10.2.2 Symbol Synchronization—Discrete Symbol Modulations, 625
10.2.3 Synchronization with Continuous-Phase Modulations (CPM), 10.2.4 Frame Synchronization, 639
10.3 Network Synchronization, 643
10.3.1 Open-Loop Transmitter Synchronization, 644
10.3.2 Closed-Loop Transmitter Synchronization, 647
10.4 Conclusion, 649
11 MULTIPLEXING AND MULTIPLE ACCESS
11.1 Allocation of the Communications Resource, 657
11.1.1 Frequency-Division Multiplexing/Multiple Access, 660
11.1.2 Time-Division Multiplexing/Multiple Access, 665
11.1.3 Communications Resource Channelization, 668
11.1.4 Performance Comparison ofFDMA and TDMA, 668
11.1.5 Code-Division Multiple Access, 672
11.1.6 Space-Division and Polarization-Division Multiple Access, 674
11.2 Multiple Access Communications System and Architecture, 676
11.2.1 Multiple Access Information Flow, 677
11.2.2 Demand Assignment Multiple Access, 678
11.3 Access Algorithms, 678
11.3.1 ALOHA, 678
11.3.2 Slotted ALOHA, 682
11.3.3 Reservation-ALOHA, 683
11.3.4 Performance Comparison ofS-ALOHA and R-ALOHA, 684
11.3.5 Polling Techniques, 686
11.4 Multiple Access Techniques Employed with INTELSAT, 689
11.4.1 Preassigned FDM/FM/FDMA or MCPC Operation, 690
11.4.2 MCPC Modes of Accessing an INTELSA T Satellite, 690
11.4.3 SPADE Operation, 693
11.4.4 TDMA in INTELSAT, 698
11.4.5 Satellite-Switched TDMA in INTELSAT, 704
11.5
11.6Multiple Access Techniques for Local Area Networks, 708
11.5.1 Carrier-Sense Multiple Access Networks, 708
11.5.2 Token-Ring Networks, 710
11.5.3 Performance Comparison of CSMA/CD and Token-Ring Networks, Conclusion, 713
12 SPREAD-SPECTRUM TECHNIQUES
12.1 Spread-Spectrum Overview, 719
12.1.1 The Beneficial Attributes of Spread-Spectrum Systems,
12.1.2 A Catalog of Spreading Techniques, 724
12.1.3 Model for Direct-Sequence Spread-Spectrum Interference Rejection, 726
12.1.4 Historical Background, 727
12.2 Pseudonoise Sequences, 728
12.2.1 Randomness Properties, 729
12.2.2 Shift Register Sequences, 729
12.2.3 PN Autocorrelation Function, 730
12.3 Direct-Sequence Spread-Spectrum Systems, 732
12.3.1 Example of Direct Sequencing, 734
12.3.2 Processing Gain and Performance, 735
12.4 Frequency Hopping Systems, 738
12.4.1 Frequency Hopping Example, 740
12.4.2 Robustness, 741
12.4.3 Frequency Hopping with Diversity, 741
12.4.4 Fast Hopping versus Slow Hopping, 742
12.4.5 FFH/MFSK Demodulator, 744
12.4.6 Processing Gain, 745
12.5 Synchronization, 745
12.5.1 Acquisition, 746
12.5.2 Tracking, 751
12.6 Jamming Considerations, 754
12.6.1 The Jamming Game, 754
12.6.2 Broadband Noise Jamming, 759
12.6.3 Partial-Band Noise Jamming, 760
12.6.4 Multiple-Tone Jamming, 763
12.6.5 Pulse Jamming, 763
12.6.6 Repeat-Back Jamming, 765
12.6.7 BLADES System, 768
12.7 Commercial Applications, 769
12.7.1 Code-Division Multiple Access, 769
12.7.2 Multipath Channels, 771
12.7.3 The FCC Part 15 Rules for Spread-Spectrum Systems,12.7.4 Direct Sequence versus Frequency Hopping, 773
12.8 Cellular Systems, 775
12.8.1 Direct Sequence CDMA, 776
12.8.2 Analog FM versus TDMA versus CDMA, 779
12.8.3 Interference-Limited versus Dimension-Limited Systems,
12.8.4 IS-95 CDMA Digital Cellular System, 782
Conclusion, 795
13 SOURCE CODING
13.1 Sources, 804
13.1.1 Discrete Sources, 804
13.1.2 Waveform Sources, 809
13.2 Amplitude Quantizing, 811
13.2.1 Quantizing Noise, 813
13.2.2 Uniform Quantizing, 816
13.2.3 Saturation, 820
13.2.4 Dithering, 823
13.2.5 Nonuniform Quantizing, 826
13.3 Differential Pulse-Code Modulation, 835
13.3.1 One-Tap Prediction, 838
13.3.2 N-Tap Prediction, 839
13.3.3 Delta Modulation, 841
13.3.4 Sigma-Delta Modulation, 842
13.3.5 Sigma-Delta A-to-D Converter (ADC), 847
13.3.6 Sigma-Delta D-to-A Converter (DAC), 848
13.4 Adaptive Prediction, 850
13.4.1 Forward Prediction, 851
13.4.2 Synthesis/Analysis Coding, 852
13.5 Block Coding, 853
13.5.1 Vector Quantizing, 854
13.6 Transform Coding, 856
13.6.1 Quantization for Transform Coding, 857
13.6.2 Subband Coding, 857
13.7 Source Coding for Digital Data, 859
13.7.1 Properties of Codes, 860
13.7.2 Huffman Codes, 862
13.7.3 Run-Length Codes, 866
13.8 Examples of Source Coding, 870
13.8.1 Audio Compression, 870
13.8.2 Image Compression, 875
13.9 Conclusion, 884
14 ENCRYPTION AND DECRYPTION
14.1 Models, Goals, and Early Cipher Systems, 891
14.1.1 A Model of the Encryption and Decryption Process, 893
14.1.2 System Goals, 893
14.1.3 Classic Threats, 893
14.1.4 Classic Ciphers, 894
14.2
 The Secrecy of a Cipher System, 897
14.2.1 Perfect Secrecy, 897
14.2.2 Entropy and Equivocation, 900
14.2.3 Rate of a Language and Redundancy, 902
14.2.4 Unicity Distance and Ideal Secrecy, 902
14.3
 Practical Security, 905
14.3.1 Confusion and Diffusion, 905
14.3.2 Substitution, 905
14.3.3 Permutation, 907
14.3.4 Product Cipher Systems, 908
14.3.5 The Data Encryption Standard, 909
14.4
 Stream Encryption, 915
14.4.1 Example of Key Generation Using a Linear
Feedback Shift Register, 916
14.4.2 Vulnerabilities of Linear Feedback Shift Registers, 917
14.4.3 Synchronous and Self-Synchronous Stream
Encryption Systems, 919
14.5
 Public Key Cryptosystems, 920
14.5.1 Signature Authentication using a Public Key Cryptosystem,14.5.2 A Trapdoor One-Way Function, 922
14.5.3 The Rivest-Shamir-Adelman Scheme, 923
14.5.4 The Knapsack Problem, 925
14.5.5 A Public Key Cryptosystem based on a Trapdoor Knapsack,14.6
 Pretty Good Privacy, 929
14.6.1 Triple-DBS, CAST, and IDEA, 931
14.6.2 Diffie-Hellman (Elgamal Variation) and RSA, 935
14.6.3 PGP Message Encryption, 936
14.6.4 PGP Authentication and Signature, 937
14.7  Conclusion, 940
15 FADING CHANNELS
15.1 The Challenge of Communicating over Fading Channels, 945
15.2 Characterizing Mobile-Radio Propagation, 947
15.2.7 Large-Scale Fading, 951
15.2.2 Small-Scale Fading, 953
15.3 Signal Time-Spreading, 958
15.3.7 Signal Time-Spreading Viewed in the Time-Delay Domain, 958
15.3.2 Signal Time-Spreading Viewed in the Frequency Domain, 960
15.3.3 Examples of Flat Fading and Frequency-Selective Fading, 965
15.4 Time Variance of the Channel Caused by Motion, 966
15.4.7 Time Variance Viewed in the Time Domain, 966
15.4.2 Time Variance Viewed in the Doppler-Shift Domain, 969
15.4.3 Performance over a Slow-and Flat-Fading Rayleigh Channel, 975
15.5 Mitigating the Degradation Effects of Fading, 978
75.5.7 Mitigation to Combat Frequency-Selective Distortion, 980
75.5.2 Mitigation to Combat Fast-Fading Distortion, 982
15.5.3 Mitigation to Combat Loss in SNR, 983
15.5.4 Diversity Techniques, 984
15.5.5 Modulation Types for Fading Channels, 987
15.5.6 The Role of an Interleaver, 988
15.6 Summary of the Key Parameters Characterizing Fading Channels, 992
15.6.7 Fast Fading Distortion: Case 1, 992
15.6.2 Frequency-Selective Fading Distortion: Case 2, 993
15.6.3 Fast-Fading and Frequency-Selective Fading Distortion: Case 3, 993
15.7 Applications: Mitigating the Effects of Frequency-Selective Fading, 996
15.7.7 The Viterbi Equalizer as Applied to GSM, 996
15.7.2 The Rake Receiver as Applied to Direct-Sequence
Spread-Spectrum (DS/SS) Systems, 999
15.8 Conclusion, 1001
A A REVIEW OF FOURIER TECHNIQUES
A.I  Signals, Spectra, and Linear Systems, 1012
A.2 Fourier Techniques for Linear System Analysis, 1012
A2.1 Fourier Series Transform, 1014
A.2.2 Spectrum of a Pulse Train, 1018
A.2.3 Fourier Integral Transform, 1020
A.3  Fourier Transform Properties, 1021
A.3.1 Time Shifting Property, 1022
A.3.2 Frequency Shifting Property, 1022
A.4 Useful Functions, 1023
A.4.1 Unit Impulse Function, 1023
A.4.2 Spectrum of a Sinusoid, 1023
A.5  Convolution, 1025
A5.1 Graphical Example of Convolution, 1027
A.5.2 Time Convolution Property, 1028
A.5.3 Frequency Convolution Property, 1030
A.5.4 Convolution of a Function with a Unit Impulse, 1030
A.5.5 Demodulation Application of Convolution, 1031
A.6 Tables of Fourier Transforms and Operations, 1033
B FUNDAMENTALS OF STATISTICAL DECISION THEORY
B.I Bayes' Theorem, 1035
B.1.1 Discrete Form of Bayes'Theorem, 1036
B.1.2 Mixed Form of Bayes'Theorem, 1038
B.2 Decision Theory, 1040
B.2.7 Components of the Decision Theory Problem, 1040
B.2.2
 The Likelihood Ratio Test and the Maximum
A Posteriori Criterion, 1041
B.2.3
 The Maximum Likelihood Criterion, 1042
B.3
 Signal
 Detection Example, 1042
B.3.1
 The Maximum Likelihood Binary Decision, 1042
B.3.2
 Probability of Bit Error, 1044
C RESPONSE OF A CORRELATOR TO WHITE NOISE
D OFTEN-USED IDENTITIES
E s-DOMAIN, z-DOMAIN AND DIGITAL FILTERING
E.I The Laplace Transform, 1051
E.1.1 Standard Laplace Transforms, 1052
E.1.2 Laplace Transform Properties, 1053
E.1.3 Using the Laplace Transform, 1054
E.1.4 Transfer Function, 1055
E.1.5 RC Circuit Low Pass Filtering, 1056
E.1.6 Poles and Zeroes, 1056
E.1.7 Linear System Stability, 1057
E.2 The z-Transform, 1058
E.2.1 Calculating the z-Transform, 1058
E.2.2 The Inverse z-Transform, 1059
E.3 Digital Filtering, 1060
E.3.1 Digital Filter Transfer Function, 1061
E.3.2 Single Pole Filter Stability, 1062
E.3.3 General Digital Filter Stability, 1063
E.3.4 z-Plane Pole-Zero Diagram and the Unit Circle, 1063
E.3.5 Discrete Fourier Transform of Digital Filter Impulse Response,
E.4 Finite Impulse Response Filter Design, 1065
E.4.1 FIR Filter Design, 1065
E.4.2 The FIR Differentiator, 1067
E.5 Infinite Impulse Response Filter Design, 1069
E.5.1 Backward Difference Operator, 1069
E.5.2 HR Filter Design using the Bilinear Transform,E.5.3 The IIR Integrator, 1071
LIST OF SYMBOLS
INDEX


Although the microcontroller section goes off the rails with impossible to obtain stuff.

The MCU section always was weak, especially w.r.t. software; I don't see how it could be othewise.

TAoMCU is a book waiting to be written.

[tggzzz]

It's in the kitchen, along with your reading glasses.

Solved: they are dangling around my neck when not required. Put them over head when I get up, take them off when I go to bed.

I buy a range of strengths from the manufacturer (Foster Grant), £10 individually or £4 each if you buy a dozen.

[med6753]

Face facts you old farts. You need glasses to see anything within 3 feet. Bite the bullet and get glasses with progressive lens. That way you wear them all the time and don't have to worry where you left them or have them dangling on a strap like an old spinster librarian. 

Yes, they take a while to get used to them but I got them years ago and never looked back. 

[mnementh]

And I kindly invite them to go piss up a rope. 

Ah, is this some pastime from your youth? Like seeing who can piss the highest? 

It's a kinder, gentler way of saying "fuck off". When I broke free of the shackles of my past relationship in 2010 I swore that no one would ever again tell me what I could do and when I could do it. These past 10 years have been the best of the last 40. 

med has come to terms with the fact that he's an insufferable a barely sufferable ass that nobody can tolerate for more than a weekend.  Instead of retreating inwards and becoming an utterly antisocial hermit, he's sought out and found a communal venue and a member of the opposite gender with which he can successfully make guerilla attacks on sociability, yet maintain his generally asocial nature.

I applaud his hard work; 'tis a razor's edge he walks, and for the most part he does so with no small measure of dignity.

mnem
Been dere, dunnat, burned da shirt. Whilest I was wearing it.

[SilverSolder]

Face facts you old farts. You need glasses to see anything within 3 feet. Bite the bullet and get glasses with progressive lens. That way you wear them all the time and don't have to worry where you left them or have them dangling on a strap like an old spinster librarian. 

Yes, they take a while to get used to them but I got them years ago and never looked back. 

I have pairs of glasses in every area...  in the lab, by the PC, in the garage, by the bed...   and the rule is, they are not allowed to leave that area.  Job done!

[bd139]

To me a good description of TAoE that, only greybeards will understand, is to remember the old Markus compendiums of circuits. They contained thousands of "naked" schematics, which sounds exactly what a practicing engineer might want so they didn't have to (poorly) reinvent a wheel, and to solve their problem using a circuit that would probably work well.

But in practice the Markus' compendiums were a great disappointment and of little use, because there was no description of how the circuits worked, nor their performance, nor their limitations.

TAoE avoids that trap by having the explanations. Hence TAoE useful when you want to find a circuit that Just Works.

OTOH, TAoE by design is not a good book for understanding fundamental electronics and theory, nor for understanding the depths of any particular subject.

Spot on. The accompanying lab book is designed for the latter. There's a lot to learn in there as well. I own a copy of that too.

No lab book nor the x-chapters could satisfy what I'm thinking of there. Examples would be things like Sklar's DIGITAL COMMUNICATIONS Fundamentals and Applications with contents: 

... snip contents ...

Oooh that's a nice book. I like that. A lot of that stuff is missing from AoE to get some true understanding of how to apply what you learn from it. I always thought there should be a tutorial book which sort of goes:

1. Systems and modularity.
2. Signals in systems.
3. Representing signals in electronic systems.
4. Only now get to what the hell a resistor is.
.... 1000 pages later...
76. The microprocessor.
77. Programming microprocessors
78. applying modularity to software
79. avoiding cargo cults.

Does not exist.

Although the microcontroller section goes off the rails with impossible to obtain stuff.

The MCU section always was weak, especially w.r.t. software; I don't see how it could be othewise.

TAoMCU is a book waiting to be written.

The original laboratory manual was pretty good. I actually built the Z80 machine from it. 2nd edition student manual was ok. 3rd edition learning the art is crap. I learned a lot more from the Intel 8085 SDK / MCS-85 kit in the end though.

I have considered writing exactly that book. Unfortunately most of MCU programming these days is learning C (already well covered) and deciphering config registers (RTFDS). The following excerpt is from the latest pile of crap I'm working on. The main loop is only 11 lines long. Compare to the config code. Not a lot of reusable knowledge there:

Code: [Select]

// --------------------------------------------------------------------
// set up device
// --------------------------------------------------------------------
void setup() {
    cli();                                  // reset interrupts
    DDRB |= (1 << PB2);                     // PB2 = out
    PORTB |= (1 << PB0) & (1 << PB1);       // PB0/1 = phase in
    TCNT1 = TCCR1 = 0;                      // clear timers
    OCR1C = 195;                            // F_CPU/2048*Hz @ 10Hz
    OCR1A = OCR1C;                          // interrupt COMPA
    TCCR1 |= (1 << CTC1);                   // CTC
    TCCR1 |= (1 << CS13) | (1 << CS12);     // prescale/2048
    TIMSK |= (1 << OCIE1A);                 // enable OCIE1A
    ADMUX = (1 << ADLAR) | (1 << MUX1);     // ADC2/VCC ref/just
    ADCSRA = (1 << ADEN) | (1 << ADPS0)
          | (1 << ADPS1) | (1 << ADPS2);    // prescale /128. ADC on
    sei();                                  // enable interrupts
 }


[mnementh]

And I kindly invite them to go piss up a rope. 

I've never heard that saying before, but theres no doubt about it, it will be repeated many times on this forum  Well done to med who has shown so many times that he is always up for a laugh 

It's a corollary to "Go shit up a crooked stick..."; suggesting one should stop bothering you, go elsewhere, and engage in some fruitless, demeaning, and disgusting act that will likely end up with you humiliated and covered in filth.

Like arguing politics on the internet, only more picturesque. 

mnem

[Specmaster]

Face facts you old farts. You need glasses to see anything within 3 feet. Bite the bullet and get glasses with progressive lens. That way you wear them all the time and don't have to worry where you left them or have them dangling on a strap like an old spinster librarian. 

Yes, they take a while to get used to them but I got them years ago and never looked back. 

I have a pair of progressives that I use for driving and also a pair of reading glasses that I use for computer / bench / reading use. The progressives are also supposed to double up as reading glasses, which they can if the reading material  is on the bench, or held low in front of me. When it comes doing anything on the bench or on the computer they just give me headaches, eye strain and looking at the monitor, which sitting on a monitor shelf, at head height when sitting, means I have to tip my head so far back that I get neck ache as well.
So it looks like I'll have to continue with having 2 pairs of glasses prescribed each time, and I'm currently overdue another eye check, so expect a further hit in the wallet. 

[med6753]

And I kindly invite them to go piss up a rope. 

Ah, is this some pastime from your youth? Like seeing who can piss the highest? 

It's a kinder, gentler way of saying "fuck off". When I broke free of the shackles of my past relationship in 2010 I swore that no one would ever again tell me what I could do and when I could do it. These past 10 years have been the best of the last 40. 

med has come to terms with the fact that he's an insufferable a barely sufferable ass that nobody can tolerate for more than a weekend.  Instead of retreating inwards and becoming an utterly antisocial hermit, he's sought out and found a communal venue and a member of the opposite gender with which he can successfully make guerilla attacks on sociability, yet maintain his generally asocial nature.

I applaud his hard work; 'tis a razor's edge he walks, and for the most part he does so with no small measure of dignity.

mnem
Been dere, dunnat, burned da shirt. Whilest I was wearing it.

How observant of you. And you're god damn right. You must be jealous. 

[Cerebus]

No lab book nor the x-chapters could satisfy what I'm thinking of there. Examples would be things like Sklar's DIGITAL COMMUNICATIONS Fundamentals and Applications

And yet that itself is only really a tour of the sub-territory it covers. A quick glance at it and, if I pick on the chapter I'm best equipped to judge - the chapter on cryptography, it still only really provides a survey of the topic. (I'd be horrified if someone tried to design and build a secure comms link with only that chapter to work from.) Like I said, a really quick skim, so I can't comment if any of the other chapters are truly more in depth.

My journey through learning various things suggests that one starts with a text that offers a very broad brush of some field of study. If you're lucky you manage to find one that gets the horse before the cart (e.g. In electronics equips you with Ohm's law and friends and some idea what passive components do, then basic active circuits before hitting you up with a mathematical model of the PN junction).

If your first text is any good it leaves you with questions that it has hinted have answers - if it's really good it has lists of accessible references wherein you might find some of those answers. So you grab a small shelf full of books that cover sub-topics in more detail. Then you move on to more specialised texts (or if you chose one or more of your 'second level' books badly you might have to backtrack half a level). Eventually you end up reading highly specialised monographs or scouring journals and papers to find the meat of specific areas where you have an immediate interest or problem to solve.

[mnementh]

I got my fresh cup of coffee and deciding what I will or will not do today. 

I repeat my previous answer. Bacon is the answer.

Don't have any...maybe go get some. 

Don't forget to write yourself another note or you'll wind up sitting in the car just feeling the rumble of the motor under your arse for 10 minutes trying to remember where you were going. You know, like the dog who stops halfway across the living room because he forgot where he was going; so instead sits down and starts to lick his balls.

mnem
Fuck... where did the living room get off to now...?

[Cerebus]

76. The microprocessor.
77. Programming microprocessors
78. applying modularity to software
79. avoiding cargo cults.

80. concealing user's and coworker's corpses

[Zucca]

This will be the next one:

https://www.ebay.com/itm/161918867021

is it a scam ot not?

[mnementh]

And I kindly invite them to go piss up a rope. 

Ah, is this some pastime from your youth? Like seeing who can piss the highest? 

It's a kinder, gentler way of saying "fuck off". When I broke free of the shackles of my past relationship in 2010 I swore that no one would ever again tell me what I could do and when I could do it. These past 10 years have been the best of the last 40. 

med has come to terms with the fact that he's an insufferable a barely sufferable ass that nobody can tolerate for more than a weekend.  Instead of retreating inwards and becoming an utterly antisocial hermit, he's sought out and found a communal venue and a member of the opposite gender with which he can successfully make guerilla attacks on sociability, yet maintain his generally asocial nature.

I applaud his hard work; 'tis a razor's edge he walks, and for the most part he does so with no small measure of dignity.

mnem
Been dere, dunnat, burned da shirt. Whilest I was wearing it.

How observant of you. And you're god damn right. You must be jealous. 

Naaahhh... just a fellow misanthrope who got unbelievably lucky and found the love of a truly good woman. If not for her I'd STILL be there, doing exactly the same as you.

mnem
How many times do I have to tell you... You're an asshole, but you're my kind of asshole...? 

[mnementh]

Face facts you old farts. You need glasses to see anything within 3 feet. Bite the bullet and get glasses with progressive lens. That way you wear them all the time and don't have to worry where you left them or have them dangling on a strap like an old spinster librarian. 

Yes, they take a while to get used to them but I got them years ago and never looked back. 

Not in my case; I need glasses to see anything further away than my elbow. I've lived with this defective vision and Coke-bottle-bottom glasses (or contacts so high a scrip I have to special order them) all my life.

Wanna trade eyeballs?

mnem
There's more than one reason I've learned to "see" with my fingertips; it's not JUST that being a mechanic you're ALWAYS working BEHIND something that's in front of you...

[mnementh]

This will be the next one:

https://www.ebay.com/itm/161918867021

is it a scam ot not?

It's Pearson Publishing; the school textbook arm of the pro-corporate ultra-conservative propaganda machine here in the US. They literally have rewritten US history, painting John Calvin as a fucking hero and trivialising the role of slavery in the historical economies of our developing nation to whitewash the atrocities committed therein in the pursuit of profit.

If they're publishing it, it's because it in some way prepares young minds for indentured servitude to the corporatocracy; whether it be political propaganda or fast-track narrow-focus training to make one useful for only a single specialty that is in high demand ATM, but which skillset will likely make you a useless pariah in a decade if you don't force yourself to diversify your education.

TL/DR: If Pearson Publishes it, there's a pro-corporate agenda behind it. Follow the money, look for and find that agenda before buying the book or buying into its contents.

mnem
*~ Illegitimi non carborundum ~*

[mnementh]

76. The microprocessor.
77. Programming microprocessors
78. applying modularity to software
79. avoiding cargo cults.

80. concealing user's and coworker's corpses

Spoken like a true disciple of Simon Travaglia. 

mnem
Who am I kidding? Simon would be Cerebus' disciple; not the other way around...

[tggzzz]

TAoMCU is a book waiting to be written.

The original laboratory manual was pretty good. I actually built the Z80 machine from it. 2nd edition student manual was ok. 3rd edition learning the art is crap. I learned a lot more from the Intel 8085 SDK / MCS-85 kit in the end though.

I have considered writing exactly that book. Unfortunately most of MCU programming these days is learning C (already well covered) and deciphering config registers (RTFDS). The following excerpt is from the latest pile of crap I'm working on. The main loop is only 11 lines long. Compare to the config code. Not a lot of reusable knowledge there:

Indeed; that code is all "which button do I push to frobnitz the squirdle" stackexchange fodder.

OTOH learning C is far from sufficient w.r.t. the art of programming. I'd argue an appropriate set of realtime/embedded design patterns would be a better starting point.
(I'd also argue that C is an antipattern, but that's another lost battle).

[Specmaster]

Just hooked up my new hub unit and the speeds that I'm now getting are 552/41, I have to do some serious downloading later to see how long to download a film etc. Analysing my network, I'm the only one who can access that speed, the rest of the family are connected and a max speed of 100/10 due to the hardware. I have a 16 way 1Gb switch which feeds out to a series of 100/10 local hubs because of the various internet connected devices at each location, so I  may have to  invest in smaller gigabit switches.

Edit, now it's off to the shops and yes, bacon is on the list